Process of fixation of atmospheric nitrogen by metal carbid.



H. W. LAMB.

PROCESS OF FIXATION OF ATMOSPHERIC NITROGEN BY METAL CARBID.

APPLIUATION FILED MAR.18.1D144 131283630 Patented Jan.5,1915.

wunaooao WHEY WRITING LAMB, OF PORTSMOUTH, VIRGINIA.

PROCESS OF FHATION. F ATMOSPHERIC NITROGEN BY METAL GAEBID.

riaa'zea' Specification of Letters Patent.

Patented Jan. 5, il il'fi.

Application filed March 18, 1914.. Serial No. 825,590.

To all whom it may concern:

Be it known thatlf, HENRY WHrrmG LAMB, a citizen of the United States, residing at Portsmouth, county of Norfolk, State of Virginia, have invented a certain new and useful Process of Fixation of Atmos pheric Nitrogen by Metal Carbids, of which the following is a specification.

This process relates to the fixation ofatmospheric nitrogen in metallic carbid and the production of ammonia therefrom.

This process is based upon the fact that certain metal carbids are unsaturated and capable of forming additional products un-.

der the proper conditions and temperatures. Ferrous carbid lFeC has this property. Oxid of iron may be used with carbon derived from coke, coal, tar or pitch to obtain the requisite metal carbid or ferrous carbid.

The present process contemplates the fixation of atmospheric nitrogen by its absorption in liquid carbid derived from the liquefaction of oxid of iron, or oxid of iron combined with magnesium, barium or titanium, or iron oxid in combination with any other metal carbid, in the presence of coke, coal, tar, pitch or other carboniferous material, and, further, the production of ammonia by subjecting the cooled metal cyan-id to hydrogen derived, for instance, from water or superheated steam.

The nitrogen which is to be absorbed by the liquid carbid, may be derived from the atmosphere in any known or preferred manner.- I prefer to recover the nitrogen from the air by passing air over or through heated coke and to conduct theproducts of combustion to milk of lime in asuitable container such as an absorption tower, whereby the carbon monoxid or carbonic acid gas,

CO is absorbed and eliminated, leaving N free. Y I do not, however, limit myself to the manner of deriving the nitrogen which is used in my process.

In carrying out my process, oxid of iron Fe O is mixed with coke, coal, tar or p1tch,'

in suficient proportions so that upon being heated in a crucible there will be produced a coked product containing carbon in such proportions as may be indicated by the chemical formula FeC A mixture of such proportions as will produce this carbon compound is heated in a crucible in such manner that atmospheric air is excluded from contact therewith, the action being a reducing one, and as the mass passes through the zone of fusion of the crucible, it becomes liquefied and drips into an air-tight chamber as liquid metal carbidin the nature of a contact substance having the property of absorbing, combincooling, forming pigs of'solid metal cyanid which, when cool, are withdrawn from the said air-tight chamber. The cooled ig is then crushed or pulverized and Sllb]0t6d to the chemical action of water or superheated steam, which giving up its hydrogen, causes the liberation'of ammonia in gaseous form. The cumulative-yield of ammonia can be absorbed in water, compressed to a l1qu1d,,or combined with other elements, formlng compounds, composition or substitution productions, or, combined with acids to form salts or compounds, or, united in other forms of ammoniacal compounds or compositions.

The process may be augmented by exposing gaseous and solid agents, viz z nitrogen, iron oxid and coke, to the chemical change, transformation or union while under super-atmospheric pressure and at certain critical temperatures. tures may range from 1150 F. to 1850 F.

The reaction which occurs during the employment of iron oxid and coke in the transformation of nitrogen into nitrogen compounds and the delivery of the same to the hydrogen of the water or steam, in the presence of hydrogen may be illustrated by the following formulas or equations:

FeC -l-ftN Fe(GN) union of nitrogen Fe (CN) ,+3H O=2FeCO (NI-1 The carbonate of iron thus formed is to be used oyer and over again in the place of the oxld ofiron used for the original The tempera-v p hydrogen. The present invention therefore charge, in the production or formation of cyanid or ammonia from atmospheric nitrogen.- Oxid of iron only, or used collectively with any other metal of a solid nature having the property of forming a carbid and capable of taking the nitrogen and producing a cyanid can be used, instances being magnesium, barium and titanium. F urthermore, any other inert vehicle or carrier for the purpose of rendering the mass less compact and to provide a larger surface for the action of the heat used in liquefaction, can be employed without departing from the spirit of the invention.

have previously stated that my process is based upon the fact that metal carbids are unsaturated compounds and are capable of forming additional products under the proper conditions and temperatures. vFor being the structural formula for solid metal carbid, but two of the eight bonds of the two carbonsbeing satisfied by the bivalent metal carbid; the other six aresatisfied by the aflinities between the two carbons for each other, whichis'not a very strong combination. Now if this compound be heated in the presence of some element having a stronger aflinity for carbon than carbon has for itself, the bonds between the two carbons will open, and the new and stronger element will attach itself to the carbons of the'carbid toform a saturated compound, nitrogen for instance passed through heated carbid of barium or iron under proper condition will, at certain critical temperatures, combine with the carbid, forming a cyanid of barium. Thus:

- o n /CEN Bail m Ba\ or saws c N can w or Fe(CN) In the solid compound thus forniedther'ewith at certain other temperatures, the affinity of the metal base of the carbid for carbon is so changed or intensified that such nitrogen as may have been receivedor absorbed in the first instance may be delivered to'a substance capable of combining therewith, such as hydrogen of water or steam and the nitrogen hberated therefrom in nascent. form capable of uniting with the contemplates the utilization of these properties of solid metal earbid by using iron carbid or iron and coke in the chemical proportions. of a carbid, individually or in combination with other metal carbid for the securing of nitrogen and fixation of the same to and with hydrogen in a progressive or alternating and continuous manner, thereby producing a cumulative yield of ammonia.

It will be understood, in view of the foregoing specification, thatthe present invention consists, first, of the new process producing a cyanid; second, the new process of producing ammonia; third, the complete process involving the production of' the cyanid and the subsequent evolution ofammonia in gaseous form.

In the accompanying drawings; Figure 1 is a vertical section of a crucible-or retort furnace adapted for carrying out my process for producing metal cyanid; Fig. 2, a side elevation at right-angles to Fig. 1, with certain parts in section and others broken away to disclose the interior of the apparatus; and Fig. 3, a vertical section of a furnace which may be used for the derivation of nitrogen from air.

I do not limit myself to the use ofthe furnace shown in Figs. 1 and 2 for the'production of the metal cyanid, but I lay claim to this furnace as an independent invention. I do not limit myself'to any apparatus for the derivation of nitrogento be used in my; process, the furnace shown in Fig. 3 merely disclosing one method of deriving nitrogen. The nitrogen may bederived from the air. in any preferred manner. The combustion furnace shown in Fig. 3 may be used for that purpose.

1" represents a closed brick furnace having a grate 2, a suitable ash pit therebelow, a combustion chamber thereabove anda suitable lining 2 for the combustion chamber. At 7 there shown a take-off pipe or flue for the furnace gases. (30 7,

tained within the combustion chamber and surrounded thereby so. that the products of combustion may have access to the entire exterior thereof, is a fire-clay retort 8 having an air inlet pipe 10* and an outlet pipe 9 extending through the furnace wall. A

hopper 5 having a closure 5", is provided with a base or support 6 which constitutes a cover for the furnace 1 The lower part of. the hopper passes through an opening in the top of the retort-or crucible 8. Suitable doors for the ash fpit and combustion chamber are provided the coke in crucible or retort 8, in the form of nitrogen and carbon dioxid pipe 9, whence it may be conducted .to an absorption tower and the carbon dioxid.ab-.

, or the introduction of the fuel and withdrawal of the ashes.

passes into sorbed by milk of lime, leaving the nitrogen free for future use in my process which may be carried out by the furnace of Flgs. 1 and 2.

Referring to Figs. 1 and 2, 1 represents a closed fire-brick furnace having a lining 2. The furnace is braced in any suitable manner as by angle-irons 3 and tie rods 4, and it is provided with a cover 5 which 1s secured to the furnace by bolts 6 and serves as a support to an automatic hopper or magazine 7 having a suitable closure 7:. Within the furnace 1 is a bottomless crucible 8 provided with a lid 9 which has an opening to receive the lower end 10 of the hopper 7 so that the hopper may discharge into the crucible. The upper part of the crucible is of general elongated and, flat form and it then contracts as at 14?, but remains of the same length as in its upper part. From the point a the crucible again expands or flares as at b and finally has its.

open and bottom part restingin a recess in the walls 1 as at 7). Consequently there is formed below the part Z) and within the furnace, a chamber (1. At 14: and 15 are provided arched, perforated walls joining the crucible to the interior walls of the furnace 1. The walls 14 and 15 retain and reflect the heat. A combustion gas outlet 17 is for the purpose of taking off the heat and products of combustion after they have done their work on the crucible. A pipe 12 which communicates with the space or chamber d, is for the admission of free nitrogen. The furnace shown in Fig.- 3 may be utilized for the derivation of the nitrogen which is delivered to the pipe 12,

or, such nitrogen may be derived from the air by other means and delivered to pipe 12. Suitable controlling means, such as a valve, may be provided for regulating the quantity and times when the nitrogen is ad'- mitted through the pipe 12, accordingto requirements. An excess of nitrogen should be admitted under super-atmospheric pressure, preferably one plus atmospheres. Gas or gaseous fuel burners a project through the walls 1 onopposite sides of. the furnace'and are arranged so that'the flame therefrom is directed to the contracted por tion a and, upwardly against the part 14 of the crucible and below the wall 14 so that the greatest degree of heat applied to the contents of the crucible is at the point'a or substantially thereat, and, to almost as great a degree, upwardly along the walls of the part 14. The burners a are connected to their pipes 11 and are provided with valves 11.? by which they may be controlled.

Oxid of iron which is first mixed with coke, coal, tar or pitch in suflicientpropor tions to reduce the iron and producea' fc'oked the burners c acting on the mixture efiects a reduction of the iron and its combination or union with the carbon out of contact with air. This mass passes through the zone of fusion in the crucible and becomes liquefied and drips into the chamber at below. The temperature requisite to effect this liquefaction is under 1150 C. Free nitrogen under super-atmospheric pressure, being admitted through pipe 12 into chamber d, combines with the liquefied and dripping carbid. The union of the heated dripping liquid carbid with the nitrogen under super-atmospheric pressure, forms a liquid pool of cyanid, l5e(CN) which forms, as it cools, a pig P in the bottom of the furnace and may be withdrawn, when cool, through the normally closed opening 16 and afterward crushed or pulverized and then subjected to the chemical action of water or superheated steam. This latter step causes the liberation of ammonia in gaseous form and the cumulative yield of ammonia can be absorbed in water, compressed to a liquid, combined with other elements, etc., as previously explained. As previously explained, any other metal that has the property of forming a carbid and is capable of taking on nitrogen and producing a cyanid may be used with iron oxid, as oxid of iron combined with magnesium, barium or titanium, etc.

It is desirable that the nitrogen admitted through pipe 12 be in excess ofthe amount required by the fluid carbid in the formation of the cyanid and that the pressure of the nitrogen be greater than one atmosphere. so as to increase the yield in a given period of time. At 1150 C. nitrogen is absorbed somewhat slowly by the liquid carbid and asthe temperature increases, it is absorbed more rapidly and finally at about 1850 C. very energetically; in'deed almost violently. Above 1850 C. the absorption is slower and finally ceases at still higher temperatures. I do not limit myself to exact temperatures or pressures.

Having thus described. my invention,

what I claim as new and desire to secure by Letters Patent, is

1. The process of making a. cyanid, consisting, first, in producing a metal carbid by the fusion of oxid-of 'ironand a carboniferous material'an d, second, subjecting the liquid carbid thusformed to the action of nitrogen. v

. 2. The process ofmaking a cyanid, eoni gi fi tdn heating oxid ofiron in the, presence of a -Qarbomferous materlalto 'promesses duce a carbid and, second, -sqbjsct ingjhe Ins estin onywheteof, I hereunto afiix my carbid thns formed to the.,-ac t on of'nitrosignature'inpresence of. two witnesses.

gen.

The grocess of making s'oyanid. con- HENRY WHITING LAMB. 5 sisting in using oxid, ,of iron and a carboniferous substance and subjecting the lique- Witnesses: 'fied carbid. thus formed to the action of DAVIS L. HODSDEN,

nitrogen under super-atmospheric pressure. U. F. WVADDY. 

